The View from Outside

It's no trick of the light. This yellow-green apple (a French cider apple with a familiar name) really does present a two-toned face to the world.

The lower left two-thirds is distinctly darker, with a jagged but clear boundary.

That darker area has a curious translucent quality, as though the apple were a sponge that had been partially moistened. What is going on?

It's watercore.

Recall that watercore is a common condition in which extra-sweet water—tree sap—fills an apple so quickly the liquid gets between the cells of the flesh.

The watercored parts are glassy and, indeed, translucent.

The sweetness comes from natural sorbitol. Some people like it.

This isn't even a particularly bad case, but the apple's thin yellow skin makes an especially effective window into this condition.

So about liking watercore: it is sweet but not cloying. It's reputedly a delicacy in Japan.

Also, one farmer has an ingenious (though untested) idea about using it to make hard cider that is both dry and sweet.

The linchpin of the plan? Sorbitol is sweet, but unlike sugar, does not ferment. 
Hmm.